What to do when updating and this happens???

W: There is no public key available for the following key IDs:
1397BC53640DB551
W: There is no public key available for the following key IDs:
1397BC53640DB551
E: Could not open file /var/lib/dpkg/status - open (2: No such file or directory)
E: The package lists or status file could not be parsed or opened.